1. Field of the Invention
The present invention relates to a method for processing silver halide color photographic light-sensitive materials, and particularly relates to a method for forming a direct positive color image whereby stability and coloring property of color developing solutions are enhanced and increase of fog during continuous process is remarkably reduced.
2. Description of the Prior Art
Color developing solutions containing an aromatic primary amine color developing agent have been used from long ago for formation of color images, and nowadays play a central role in methods for formation of color photographic images. However, the color developing solutions have a problem that they are very succeptible to oxidation by air or metals. It is well known that when color images are formed using an oxidized developing solution, desired photographic performances cannot be obtained owing to increase of fog, change of sensitivity and gradation or the like.
Therefore, methods for enhancing preservative property of various color developing solutions have hitherto been tried, and a method wherein hydroxylamine and sulfite ion are used together is most general among them. However, by decomposition hydroxylamine generates ammonia which causes fog, and sulfite ions has a drawback that they act as a competitive compound of developing agents to inhibit coloring property. Thus either of them are not always proper as compounds for enhancing preservative property of color developing solutions (i.e., preservatives).
Particularly as for sulfite ions, though they have been used from long ago as a compound for inhibiting decomposition of hydroxylamine, they have a great coloring property - inhibiting action, and strikingly lower color density when they are used in a system where benzyl alcohol is not contained which is harmful from the viewpoint of environmental pollution and in preparation of liquids such as color developing solutions.
Alkarolamines (Japanese Patent Unexamined Published Application (hereinafter referred to as "J.P. KOKAI") No. 54-3532) and polyethyleneimines (J.P. KOKAI No. 56-94349) have been proposed as a compound usable in place of sulfite, but they could not attain an adequate effect.
Various preservatives other than hydroxylamine and sulfite and chelating agents have hitherto been tried for enhancing stability of color developing solutions. Examples of such preservatives include aromatic polyhydroxy compounds disclosed in J.P. KOKAI Nos. 52-49828, 59-160142 and 56-47038, U.S. Pat. No. 3,746,544 and the like, hydroxycarbonyl compounds disclosed in U.S. Pat. No. 3,615,503 and UK Pat. No. 1,306,176, .alpha.-aminocarbonyl compounds disclosed in J.P. KOKAI Nos. 52-143020 and 53-89425, metal salts disclosed in J.P. KOKAI Nos. 57-44148 and 57-53749, hydroxamic acid disclosed in J.P. KOKAI No. 52-27638, and the like. Examples of such chelating agents include aminopolycarboxylic acids disclosed in Japanese Patent Publication for Opposition Purpose (hereinafter referred to as "J.P. KOKOKU") Nos. 48-30496 and 44-30232, organic phosphonic acids disclosed in J.P. KOKAI No. 56-97347, J.P. KOKOKU No. 56-39359 and West Germany Pat. No. 2,227,639, phosphonocarboxylic acids disclosed in J.P. KOKAI Nos. 52-102726, 53-42730, 54-121127, 55-126241 and 55-65956 and the like, and further compounds disclosed in J.P. KOKAI Nos. 58-195845 and 58-203440, J.P. KOKOKU No. 53-40900 and the like.
However, satisfactory results have not been obtained even by use of these techniques since these compounds have only an inadequate preservative property or have a bad influence on photographic performances. Thus, excellent preservatives usable particularly in place of sulfite have been desired.
Further, it is disclosed in J.P. KOKAI Nos. 58-95345 and 59-232342 that fogs are liable to be formed during color development in color image light-sensitive materials containing an silver chlorobromide emulsion of much chlorine content. When such emulsions are used, preservatives having a low solubility in them and having more excellent preservative performances are necessary, and also in such a sense no satisfactory preservative has been found out.